The invention relates to a device for fixing an electrical connection terminal to a support.
In aircraft, some of the equipment has to be earthed. For this purpose, each item of equipment is electrically connected to the frame of the aeroplane, for example by means of metal braids or earthing wires. The ends of the metal braids or wires are received in terminals which are fixed to specific supports, the supports being mounted on the frame of the aeroplane.
In this field, fixing a terminal to a support is generally carried out by means of a screw and a nut, the terminal being held tightly between the head of the screw and a surface of the support.
In order to ensure good electrical contact between the terminal and the support, the surface of the support has to be stripped before the assembly of the screw and the nut. Once the assembly has been carried out, the stripped region of the support has to be protected against corrosion.
In addition, in order to ensure that the assembly has good resistance to vibrations, the nut is generally fixed to the support by means of rivets.
For the assembly of the screw and the nut, and for the placement of the rivets, access is required to the two sides of the support during assembly.
In addition, EP 1 376 766 in the name of the applicant discloses a device for fixing an electrical connection terminal to a support, the support being formed for example by the core of a railway rail. The device comprises a ring which is provided to be introduced into a cylindrical hole which is made in the support, a socket which is provided to be threaded in the ring and has a thread, and a threaded screw, the thread of which fits with the thread of the socket. When assembling the device, the ring is firstly positioned in the cylindrical hole in the support, and then a tensile force is exerted on the socket using a tool so as to introduce the socket into the ring with force, thereby causing radial expansion of the ring and locking of the ring in the hole. The screw is then screwed into the socket, the terminal being held tightly between the head of the screw and the ring, thus making it possible to fix the terminal to the support and to establish electrical contact between the terminal and the support.
An advantage of this fixing device is that it does not require the surface of the support to be stripped beforehand in order to ensure good electrical contact between the terminal and the support. This is because the electrical contact is produced between the ring and the inner surface of the cylindrical hole which is made in the support.
In addition, the fixing device has a reduced size.
Furthermore, in the case of the fixing device, access is not required to the two sides of the support during assembly.
However, a fixing device of this type is not traditionally used in applications which require resistance to vibrations, such as for earthing equipment on board an aircraft. This is because the vibrations to which the equipment is subjected can cause loosening of the screw which holds the terminal.
In order to prevent loosening of the screw, it would be possible to add a lock washer between the screw head and the support.
In any case, adding such a washer would result in an increase in the number of pieces forming the fixing device and in an increase in the weight of the fixing device which is unacceptable for the intended applications, said device being multiplied a large number of times in an aircraft.